Search results
Results from the WOW.Com Content Network
To permit the use of this feature, some 8051-compatible microcontrollers with internal RAM larger than 256 bytes, or an inability to access external RAM, [20] access internal RAM as if it were external and have a special function register (e.g. PDATA) that permits them to set the upper address of the 256-byte page. This emulates the MCS8051 ...
Instead, we must pass the data that was computed by SUB back to the Execute stage (i.e. to the red circle in the diagram) of the AND operation before it is normally written-back. The solution to this problem is a pair of bypass multiplexers. These multiplexers sit at the end of the decode stage, and their flopped outputs are the inputs to the ALU.
In addition, there is an 8 x 8-bit multiply (A x B), with full 16-bit result, and fractional/integer 16-bit by 16-bit divide instructions. A range of 16-bit instructions treat the A and B registers as a combined 16-bit D register for comparison (X and Y registers may also be compared to 16-bit memory operands), addition, subtraction and shift ...
Some SFR bits may be set directly using SETB/LDB instructions on the SFR's address, whereas others may require usage of specific instructions. The Intel 80196 class microcontroller has 24 SFRs, each 1 byte in size; standard Intel 8051 chips have 21 SFRs.
An AT89c2051 microcontroller in circuit. The Atmel AT89 series is an Intel 8051-compatible family of 8 bit microcontrollers (μCs) manufactured by the Atmel Corporation.. Based on the Intel 8051 core, the AT89 series remains very popular as general purpose microcontrollers, due to their industry standard instruction set, their low unit cost, and the availability of these chips in DIL (DIP ...
"Horizontal microcode has several discrete micro-operations that are combined in a single microinstruction for simultaneous operation." [1] Horizontal microcode is typically contained in a fairly wide control store; it is not uncommon for each word to be 108 bits or more. On each tick of a sequencer clock a microcode word is read, decoded, and ...
In computing, an opcode (abbreviated from operation code) [1] [2] is an enumerated value that specifies the operation to be performed. Opcodes are employed in hardware devices such as arithmetic logic units (ALUs), central processing units (CPUs), and software instruction sets. In ALUs, the opcode is directly applied to circuitry via an input ...
Material nonimplication or abjunction (Latin ab = "away", junctio= "to join") is a term referring to a logic operation used in generic circuits and Boolean algebra. [1] It is the negation of material implication .